A major use of plasticizers is in the polymer industry, for example in the polyvinyl chloride (PVC) industry. Without the availability of low cost plasticizers PVC would have little value. The plasticizers impart flexibility to the PVC. The family of phthalate esters is the predominant plasticizer used in PVC. Options to using these phthalate esters have been explored.
For example, CN-A-1199042 describes the manufacture and use of long chain alkyl benzoates as plasticizers. The starting material for the manufacture of the benzoates is methyl benzoate-rich ester mixture which is obtained from a byproduct stream of a dimethyl terephthalate (DMT) production line, and contains over 80 weight % of methyl benzoate and a low weight percentage of methyl p-toluate (MpT). Additionally, WO-A-2004/104079 describes the conversion of MpT with diols to form diesters, which are used as plasticizers.
Increasing environmental and toxicological concerns associated with phthalate esters has lead to the need to develop alternative low cost ester plasticizers that function at least equally as well as compared to phthalate esters.